Lactonic Acidity Research Articles

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

Characterization of Various Honey Samples from Different Regions of Morocco Using Physicochemical Parameters, Minerals Content, Antioxidant Properties, and Honey-Specific Protein Pattern

Honey is a bee product relatively expensive; therefore, it has been a target of adulteration by many sweeteners. In this work, we evaluated the good quality, authenticity, and content in bioactive molecules of twenty-two Moroccan honey from different botanical origins and geographical areas. For that, the following analyses were determined: the content in total protein and especially the major royal jelly protein (apalbumin 1), the analysis of total acidity, free acidity, lactonic acidity, pH, ash, Pfund, electrical conductivity, and moisture. In addition, the content of sodium, potassium, calcium, and magnesium, the dosage of polyphenols, flavones, and flavonols, and the antioxidant activities were assessed. All analyzed samples had good antioxidant activities and present a source of antioxidant compounds, the predominant mineral in all honey samples was potassium, and the physicochemical parameters are in line with the standards’ recommended limits. The content of honey samples in total protein and apalbumin 1 ranged between 212 μg/g and 4121.2 μg/g and between 27.4 μg/g and 790.82 μg/g, respectively. Overall, the detection of apalbumin 1 in all honey samples and the results of physicochemical parameters, minerals, bioactive compounds, and antioxidant activities confirm the authenticity and no adulteration of Moroccan honey.

QUALITY ASSESSMENT OF LOCALLY PRODUCED HONEY FROM USMANU DANFODIYO UNIVERSITY, SOKOTO

This study is conducted to analyze and compare the physico-chemical properties and mineral compositions of locally produced honey samples in Usmanu Danfodiyo University Sokoto with the national and international standards. To achieve these, seven samples of locally produced honey was collected from the study area. the physicochemical properties was analysed using the Official Methods of Analysis established by Association of Official Analytical Chemists while the mineral compositions of all the honey samples were determined using flame photometer and atomic absorption spectrophotometer. The results showed that the colours ranged from extra light amber to light amber; electrical conductivity from 0.06±0.01mS/cm to 1.15±0.16mS/cm and density from 1.41±0.00g/cm3 to 1.36±0.00g/cm3. On the mineral composition, the ash content was from 0.08±0.00% to 0.18±0.01%; moisture content from 3.94±0.29mg to 20.29±0.20%; total reducing sugars from 63.23±2.46% to 73.34±2.77%; free acidity from 14.48±0.53meq/kg-1 to 37.38±1.12meq/kg-1; lactonic acidity from 9.50±2.00meq/kg-1 to 15.50±1.50meq/kg-1; total acidity from 25.7±2.53 meq/kg-1 to 47.58±1.12 meq/kg-1. The physico-chemical and mineral compositions of the honeys were found to meet the established national standards. It was thus, concluded that honey from the area of study are of good quality

Official labeled and unlabeled Brazilian honey. Comparison between physicochemical, microbiological, and microscopic parameters

Introduction: Honey is a natural substance produced by bees mainly from flower nectar with high nutritional value. However, many commercialized samples are adulterated or falsified. Method: We bought twelve honeys in markets in the city of Betim (Brazil) and analyzed their acidity, pH, electrical conductivity, insoluble matter, ashes, moisture content, presence of mesophile bacteria, molds, yeasts, total coliforms, Salmonella spp. and the presence of pollen grains. Results: Considering all honey samples, the average pH was 3.8 ± 0.5 and the average free acidity was 29.8 ± 6.6 mEq/kg. Considering acidity, we found the average of lactonic acidity 6.4 ± 2.4 mEq/kg and a total average acidity of 36.2 ± 6.9 mEq/kg. The average moisture content was 19.4 ± 1.0 %, the average electrical conductivity was 391.6 ± 168.6 µS/cm, the average amount of ashes was 0.5±0.8 % and the average insoluble matter was 0.08±0.02 %. Only the moisture was significantly different between the two groups and neither honey samples had pollen grains. Conclusions: The quality parameters of the labeled and unlabeled samples were not different, although two samples of unlabeled honey were fraudulent, mainly due to the absence of pollen grains. Identifying the presence or absence of pollen in the samples is a safe, economical, and reliable first step for verifying the authenticity of the honey.

Sensory Profile and Physico-Chemical Properties of Artisanal Honey from Zulia, Venezuela.

The physico-chemical parameters and the sensory profile were determined in honeys from apiaries of the Mara and Maracaibo of Zulia State (Venezuela). The analysis of variance showed that there were no significant differences in the mean value between apiaries for most of the physicochemical parameters and sensory attributes. The obtained value for pH (3.58–4.08), free acidity (30.9–36.0 meq/kg), lactone acidity (9.0–14.3 meq/kg), total acidity (42.1–46.0 meq/kg), moisture content (19.1–20.0%), diastase activity (8.11–12.7 ºG), colour intensity (41.5–86.6 mm Pfund), hydroxymethylfurfural (15.7–26.0 mg/kg), and electrical conductivity (0.33–0.52 mS/cm) were within the criteria set by international quality regulations. The sensory profile of these honeys is characterized by being amber in colour, with a floral, acid fruit, balsamic and animal odour/aroma, a sweet, slightly acid taste, and by being fluid and of a medium persistence.

Authentication of honeys from Caramulo region (Portugal): Pollen spectrum, physicochemical characteristics, mineral content, and phenolic profile.

This study aimed to analyze the botanical origin, quality parameters, phenolic compounds, and minerals of 20 honey samples from Caramulo region (Portugal). Six samples were monofloral from Eucalyptus sp., being this one the predominant pollen in the analyzed samples, followed by Castanea sativa. The average values obtained for the physicochemical parameters were as follows: 4.7pH; 16.8% moisture; 81.4 Brix; 0.3% ash; 512.8 µS/cm electrical conductivity; 22.6 meq/kg free acidity; 12.4 meq/kg lactonic acidity; 35.1 meq/kg total acidity; 2.1mg/kg hydroxymethylfurfural; and 16.3 °Gothe for diastase activities. A total of 18 phenolics were determined by high-performance liquid chromatography-diode array detector. Hydroxycinnamic acid derivatives and protocatechuic acid were the major ones. Nine minerals were detected by atomic absorption spectrometry; potassium and phosphorus were the predominant mineral elements. This is the first study about honeys from Caramulo region, which revealed to have a good quality and be a rich source of essential minerals and phenolics. PRACTICAL APPLICATION: The interest in the analysis of honey has increased significantly in recent years, concerning its characterization, safety implications, and health impact. Given these facts, the authentication of honeys, based on the geographical and botanical origins, has been assuming great importance, being mainly associated with high-quality honeys. Therefore, we decided to analyze physicochemical parameters, phenolic composition, and mineral content of 20 Caramulo honey samples. Our results indicate that Caramulo honeys possess high-quality levels, good freshness, maturity, and proper processing, and are also rich in several bioactive substances with health-promoting properties, including phenolic compounds, potassium, and phosphorus.

Physicochemical Properties, Mineral Content, Antioxidant Activities, and Microbiological Quality of Bupleurum spinosum Gouan Honey from the Middle Atlas in Morocco

Monofloral honeys (Bupleurum Spinosum) collected from different geographical locations of Moroccan Middle Atlas were evaluated for various potential attributes. For physicochemical parameters, the results showed the following values: pH (4.02–4.81); free acidity (12.16–31.85 mEq/kg); lactonic acidity (4.98–14.14 mEq/kg); total acidity (18.37–45.53 mEq/kg); moisture (15.81–19.20%); ash (0.21–0.55); electrical conductivity (427.38–682.16 mS/cm); diastasic activity (10.76–26.01); TSS (80.40–84.20%); melanoidins (0.21–1.15), and Pfund scale (30.47–175.53 mm). Potassium was the most important mineral among the tent evaluated elements, followed by sodium and calcium. All tested samples have high antioxidant activities and correlate with phenols, flavonoids, and ascorbic acid content. In regards to safety (sulfite-reducing clostridia and Salmonella spp.) and sanitary quality (faecal coliforms), all honey samples were negative. In addition, low counts of yeast and molds were detected, and the values of total aerobic mesophilic bacteria and Bacillus Sp. confirm the good quality of honey. The outcome of this study showed that all samples have good physicochemical properties, high antioxidant activities, and acceptable microbiological state, respecting the quality control criteria set by the international norms.

Indication of the geographical origin of honey using its physicochemical characteristics and multivariate analysis.

Honey from different botanical sources presents a great variability in chemical composition, physical properties, and sensorial attributes. The association between honey qualities and its geographical origin allows the recognition of honey, and beekeepers are economically benefited. The objective of this study was to evaluate the physicochemical characteristics of honey produced in Ortigueira, Brazil and to compare it with the honey produced in the neighboring localities for the request of geographical indication certification. In the 112 honey samples collected between 2010 and 2013 from Ortigueira and the neighboring localities, moisture acidity, pH, hydroxymethyl furfural (HMF), diastase activity (DA), sugars, proline (Pro), electrical conductivity (EC), color absorbance at 635nm (C635), and Cielab color parameters were evaluated. HMF, reducing sugars (RS), total sugars (TS), proline, and color parameters (L*, a* and b*) were significantly different in Ortigueira 2010 honey seasons. Principal component analysis separated assapeixe (Vernonia sp) and capixingui (Croton floribundus) honeys from wild honeys (polyfloral). In addition, HMF, RS, L*, and lactonic acidity values promoted the separation between assapeixe and capixingui honeys. Ortigueira honey differs significantly from honeys from neighboring locality in pH, proline, HMF, DA, EC, RS, sucrose, TS, free and total acidity, and color parameters (C635, L*, a*, b*). The multivariate analysis applied to variables was efficient to discriminate honeys from different botanical sources and different locals, and is recommended for studies on the geographical indication of honey.

Raman Spectroscopy and Chemometric Modeling to Predict Physical-Chemical Honey Properties from Campeche, Mexico.

In this work, 10 chemometric models based on Raman spectroscopy were constructed to predict the physicochemical properties of honey produced in the state of Campeche, Mexico. The properties of honey studied were pH, moisture, total soluble solids (TSS), free acidity, lactonic acidity, total acidity, electrical conductivity, Redox potential, hydroxymethylfurfural (HMF), and ash content. These proprieties were obtained according to the methods described by the Association of Official Analytical Chemists, Codex Alimentarius, and the International Honey Commission. For the construction of the chemometric models, 189 honey samples were collected and analyzed in triplicate using Raman spectroscopy to generate the matrix data [X], which were correlated with each of the physicochemical properties [Y]. The predictive capacity of each model was determined by cross validation and external validation, using the statistical parameters: standard error of calibration (SEC), standard error of prediction (SEP), coefficient of determination of cross-validation (R2cal), coefficient of determination for external validation (R2val), and Student’s t-test. The statistical results indicated that the chemometric models satisfactorily predict the humidity, TSS, free acidity, lactonic acidity, total acidity, and Redox potential. However, the models for electric conductivity and pH presented an acceptable prediction capacity but not adequate to supply the conventional processes, while the models for predicting ash content and HMF were not satisfactory. The developed models represent a low-cost tool to analyze the quality of honey, and contribute significantly to increasing the honey distribution and subsequently the economy of the region.

Determination of Quality Parameters of Honey from Taraba State – Nigeria

The aim of this study is to evaluate the quality parameters of honey samplescollected from different locations in Taraba State, in terms of physicochemical properties such as colour, specific gravity, refractive index, viscosity, moisture content, ash content, free acidity, lactone acidity, total acidity, pH value, electrical conductivity, sugar content, hydroxymethylfurfural (HMF) content, diastase activity and protein content. The results showed that mean values of honey temperature ranges from29.4± 0.49 to 38.5± 0.27°C; colour, light amber to dark amber; specific gravity, 1.30±0.01 to 1.48±0.01; refractive index, 1.47±0.01 to 1.50±0.02; viscosity, 23.2±0.10 to 34.2±0.10 Pas; moisture content, 11.27±0.01 to 19.70±0.01%; ash content, 0.14±0.01 to 0.52±0.04%; free acidity, 14.86±0.03 to 32.74±0.01 meqkg^-1; lactone acidity, 1.58±0.01 to 3.71±0.03meqkg^-1; total acidity, 16.44±0.03 to 35.52±0.01 meqkg^-1;pH value, 3.67±0.02 to 5.10±0.19; electrical conductivity, 0.08±0.01 to 0.48±0.02 mScm^-1; total reducing sugar content, 74.30±0.03 to 82.30±0.04%; sucrose content, 3.58±0.02 to 4.71 ±0.02%; hydroxymethylfurfural (HMF) content, 10.51±0.04to 14.31±0.02 mgkg^-1; diastase activity, 23.20±0.02 to 26.46±0.02 Go and protein content, 0.74±0.01 to 0.85±0.01%. The quality parameters were subjected to a one way ANOVA at p ≤ 0.05. There were significant differences in the colour, specific gravity, viscosity, moisture content, ash content, free acidity, lactone acidity, total acidity, pH value and electrical conductivity of the honey samples while refractive index, sugar content, hydroxymethylfurfural (HMF) content, diastase activity and protein content showed no significant differences. A 2-tailed F-LSD test at 5% level of significance shows that the differences between the mean values are statistically significant for all the locations for temperature, viscosity, moisture content, free acidity, lactone acidity, total acidity and electrical conductivity of the honey samples while colour, specific gravity and ash content shows that the differences between themean values are statistically significant for most of the sample locations. The honey samples present a good level of quality because the physicochemical values were in the range of approved limits (conforming to codex standards) for all honey samples. It was indicated that honey from the area will be suitable for exportation when processed appropriately.

Discrimination of Clover and Citrus Honeys from Egypt According to Floral Type Using Easily Assessable Physicochemical Parameters and Discriminant Analysis: An External Validation of the Chemometric Approach.

Twenty-two honey samples, namely clover and citrus honeys, were collected from the greater Cairo area during the harvesting year 2014–2015. The main purpose of the present study was to characterize the aforementioned honey types and to investigate whether the use of easily assessable physicochemical parameters, including color attributes in combination with chemometrics, could differentiate honey floral origin. Parameters taken into account were: pH, electrical conductivity, ash, free acidity, lactonic acidity, total acidity, moisture content, total sugars (degrees Brix-°Bx), total dissolved solids and their ratio to total acidity, salinity, CIELAB color parameters, along with browning index values. Results showed that all honey samples analyzed met the European quality standards set for honey and had variations in the aforementioned physicochemical parameters depending on floral origin. Application of linear discriminant analysis showed that eight physicochemical parameters, including color, could classify Egyptian honeys according to floral origin (p < 0.05). Correct classification rate was 95.5% using the original method and 90.9% using the cross validation method. The discriminatory ability of the developed model was further validated using unknown honey samples. The overall correct classification rate was not affected. Specific physicochemical parameter analysis in combination with chemometrics has the potential to enhance the differences in floral honeys produced in a given geographical zone.

Honey quality of Melipona sp. bees in Acre, Brazil

La miel de abejas sin aguijón (Melipona sp.) es considerada un producto nutritivo, medicinal, económico y valorizado en el mercado informal del Brasil, impulsado por la creciente demanda de productos naturales. Sin embargo, las características fisicoquímicas del producto aún son poco conocidas. Por lo tanto, el objetivo de este estudio fue evaluar las características fisicoquímicas de la miel de abejas sin aguijón producidas en Cruzeiro do Sul, Acre, Brasil. Las mieles se analizaron de acuerdo a la metodología recomendada por el Ministério da Agricultura, Pecuária e Abastecimento, y los siguientes parámetros se establecieron: humedad, azúcares totales, azúcares reductores, sacarosa aparente, ceniza, proteína cruda, actividad de la diastasa, grados Brix, acidez libre, acidez lactónica, acidez total, pH, hidroximetilfurfural, conductividad eléctrica, color y reacciones de Lugol, Lund y Fiehe. Los resultados de este trabajo demuestran que estos parámetros no son adecuados para todas las muestras, siendo incompatibles con las normas establecidas, indicando que la legislación vigente para Apis mellifera no es adecuada para todas las variables analizadas, principalmente el contenido de humedad, lo que corrobora la necesidad de una estandarización propia para la miel de abejas sin aguijón. Se demostró también que no se encontró ningún tipo de adulteración en las mieles analizadas.

Characterization of Portuguese honey from Castelo Branco region according to their pollen spectrum, physicochemical characteristics and mineral contents.

The aim of this work was to evaluate the quality of 16 honey samples from Castelo Branco region (Portugal). Twelve are monofloral from Calluna vulgaris, Erica, Lavandula, Echium and Campanula. The mean values obtained for physicochemical parameters were: 3.82 pH; 16.80% moisture; 81.6°Brix; 0.21% ash; 357.6μScm-1 electrical conductivity; 33.7meq/kg free acidity; 5.7meq/kg lactonic acidity; 39.3meq/kg total acidity; 9.11mg/kg HMF; 21.3 IN invertase and 9.0° Gothe for diastase activities. The results indicate a good quality, adequate processing, good maturity and freshness of honey. Additionally, the determination of mineral contents revealed that the K was the major element. Mean values obtained were (mg/kg): Ca, 28.36; K, 701.87; Mg, 74.00; Na, 31.04; Fe, 097; Cu, 0.65; Zn, 1.23; Mn, 2.78 and P, 48.80. Among the overall determined parameters, CB2 stands out by its high values in minerals, pH, moisture, ash, electrical conductivity and enzyme activity.

Ceratonia siliqua honeys from Morocco: Physicochemical properties, mineral contents, and antioxidant activities

Physicochemical properties, main mineral content, and antioxidant activity were determined for eight floral carob honeys collected from different geographical regions of Morocco. Moroccan honeys showed good chemical and nutritional qualities, fulfilling the criteria described in the standard codex for honey. The percentages obtained for ashes were (0.13–0.69%), electrical conductivity (0.36–1.35 mS/cm), water content (17.30–22.80%), pH (4.17–5.05), free acidity (11.0–42.50 meq/kg), lactone acidity (4.0–16.50 meq/kg), and for total acidity (16.50–59.50 meq/kg). In addition, minerals such as K, Na, Mg, Cu, Zn, and Ca of honey samples were determined and potassium was the major mineral in all samples. The antioxidant activities based on the free radical scavenging, reducing power, and total antioxidant activity were investigated, and the antioxidant capacity of the honey samples was correlated with their biochemical constituents such as total phenol and flavonoids content, and the best antioxidant capacity was confirmed by the honey from Taounate.

Physicochemical and biochemical properties of honeys from arid regions

This study was conducted to evaluate the quality of 11 honeys from arid regions for first time, and compare it with 5 different honeys from non-arid regions. Mean values obtained for physicochemical parameters were: pH 4.76±0.55; 17.32±1.8% moisture; 80.95±1.60°Brix sugar; 69.05±4.41% total sugar; 413.81±178.48μScm−1 electrical conductivity; 17.58±7.68meq/kg free acidity; 11.05±3.18meq/kg lactonic acidity; 28.63±9.6meq/kg total acidity; 12.66±20.39mg/kg HMF; 0.58±0.03 water activity; and 0.98±0.62 colour intensity. Potassium was the major mineral (1760.54±685.24mg/kg). All the samples showed considerable significant variations with reference to their physicochemical and biochemical properties, moreover, the total free amino acids and total carotenoids were 61.13±63.16mg/100g and 4.07±10.05μg/100g respectively. Acrylamide was detected only in one sample at 2.39±0.22μg/kg.

English

The characterization of some Algerian northeast honey was carried out on the basis of their physico-chemical properties: moisture, hydroxymethylfurfural, diastase activity, pH, free, total and lactonic acidity, electrical conductivity, mineral and proline content. Studied samples are found to be low in moisture and therefore safe from fermentation, low in HMF level and high in diastase activity. Additionally, the diastase activity and the HMF content are widely recognized parameters indicating the freshness of honey. The quality of honey samples differs on account of various factors such as season, packaging and processing conditions, floral source, geographical origin and storage period. It is important that precautions should be taken to ensure standardization and rationalization of beekeeping techniques, manufacturing procedures and storing processes to improve honey quality. Key words: Honey, physico-chemical characterisation, HMF, diastase activity.

Jujube Honey from China: Physicochemical Characteristics and Mineral Contents

We investigated and compared the physicochemical properties (moisture, color, ash, pH, electrical conductivity, free acidity, lactonic acidity, total acidity, fructose, glucose, sucrose, diastase activity, and HMF) and mineral contents (Al, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, As, Cd, Pb, and Zn), as well as total proline and total protein contents of 23 jujube honey samples collected from different regions of China. The mineral content was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The physicochemical values were in the range of approved limits (conforming to EU legislation) in all 23 samples. The physicochemical properties of jujube honey showed significant variations among samples. The mean pH value of the jujube honeys was 6.71. The most abundant minerals were potassium, calcium, sodium, and magnesium, ranging between 1081.4 and 2642.9, 97.1 and 194.2, 7.79 and 127.8, and 10.36 and 24.67 mg/kg, respectively, and potassium made up 71% of the total mineral content. This study demonstrated remarkable variation in physicochemical parameters and mineral contents of jujube honey, mainly depending on its geographic source.

Physicochemical properties of some honeys produced from different plants in Morocco

Seventy-three Moroccan honey samples were collected between 2005 and 2008. In this study, water content, pH, acidity (free, lactone and total acidity), electrical conductivity (EC), colour, diastase, hydroxymethylfurfural (HMF) and sugar content were all determined in different types of bee honey which include multifloral, honeydew and nine types of unifloral honeys (Euphorbia resinifera, Euphorbia echinus, Citrus, eucalyptus, carob, thyme, lavender, Ziziphus and rosemary). The moisture shows values of 14.3% and 20.2%, pH between 3.52 and 5.13, the total acidity ranges between 11.94 and 58.03meqkg−1, hydroxymethylfurfural (HMF) content shows values between 0.09 and 53.38mgkg−1; diastase values were between 4.3° and 24.6° Gothe; electrical conductivity between 119.9 and 1741μscm−1 and fructose, glucose and sucrose values range between 35.07–46.26%, 23.7–39.3% and 0.42–2.98%.A statistical analysis was carried out to classify 10 types of honeys, and identified the most significant parameters, using analysis of variance, principal component analysis (PCA) and stepwise discriminant analysis (SDA). PCA showed that the cumulative variance was 74.97% and about 88.9% of samples was correctly classified.The principal aim of this study was to contribute more to the knowledge of the Moroccan honeys by means of the analysis of chemical composition and of physical parameters. Seventy-three Moroccan unifloral, multifloral and honeydew honey samples, including types that have never been studied before, produced in different regions in Morocco (Tables 1 and 2), were analysed to define its main features.As a consequence, we present data on water content, electrical conductivity, pH, free acidity, lactone acidity, total acidity, diastase, 5-(hydroxymethyl)-2-furaldehyde (HMF) amounts, fructose, glucose and sucrose.

Influence of the temperature and the storage period on the physic-chemical parameters of Spanish honeys. Prediction of storage period using multivariate statistical analysis

Three fresh Spanish honeys (citrus, heather and honeydew honeys) were stored for three, six, nine and twelve months at 10 oC, 20 oC and 40 oC. The effect of storage conditions on honey parameters was tested by checking pH, free acidity, lactonic acidity, total acidity, proline content, diastase activity, electrical conductivity and HMF content. Principal Component Analysis (PCA) was used to group the honey samples according to the temperature conditions and storage period. The values corresponding to the physiochemical parameters of the samples stored for up to six months at 10oC and 20 oC underwent hardly any variations in comparison with the fresh samples. From nine months' storage, significant variations in the parameters analysed occurred even at room temperature. Finally, the honeys subjected to extreme storage temperatures (40 oC) showed large deteriorations even in the third month of storage. The present study employed multiple linear regressions (MLR) to predict the citrus, heather and honeydew honeys storage period based on the values of their physicochemical parameters.